JPS63261894A - Method of fixing component - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 1 line and 1 The present invention relates to a method of fixing components to a substrate.

11 Throwing Figures 5 to 7 do not show one of the conventional fixing methods for fixing electronic components such as resistors to printed circuit boards, and this fixing method will be explained based on these figures. .

As shown in FIG. 5, first, the adhesive 2 is applied to the parts fixing position on the printed circuit board 1. The adhesive 2 is an epoxy heat-curable adhesive, and is fluid in a molten state before heating. Next, as shown in FIG. 6, the terminal 3a of the resistor 3 to be fixed is inserted into the terminal insertion hole 1a formed in the printed circuit board 1, and the resistor is positioned while being brought into close contact with the adhesive 2. The printed circuit board 1 on which the electronic components including the resistor 3 are positioned in this manner is carried into a heating furnace by a conveyor or the like and heated for several minutes.

The adhesive 2 is cured by heating, and each electronic component is fixed to the printed circuit board 1.

The printed circuit board 1 on which each electronic component including the resistor 3 has been fixed is taken out from the heating furnace and immersed in a solder bath to form the circuit pattern 1 of the printed circuit board 1 as shown in FIG.
b and the terminal 3a of the resistor 3 are connected with solder 4.

As mentioned above, in the conventional fixing method, the resistor 3
When the adhesive 2 for fixing electronic components such as those on the printed circuit board 1 is still in a fluid state, the printed circuit board is transported to a heating furnace using a conveyor or the like. Therefore, the vibrations applied during the transportation of the printed circuit board may cause each electronic component to shift from its normal fixed position, and in the case of a component having a terminal such as the resistor 3, the terminal may come out of the terminal insertion hole of the printed circuit board. Even when soldering is performed, electrical continuity between each electronic component and the circuit pattern on the printed circuit board may not be achieved in some cases, resulting in a decrease in work efficiency. Further, this problem is particularly noticeable when fixing parts such as electrolytic capacitors, which have large, heavy parts and short terminals.

Other adhesives that have sufficient tack to firmly fix electronic components to printed circuit boards include solvent-volatile adhesives such as vinyl adhesives and double-sided adhesive tapes, but these are heat-resistant and It has been found that it cannot be put to practical use because it has a low temperature and melts due to the heat during soldering.

1. The present invention has been made in view of the above-mentioned points, and its purpose is to provide a fixing method that can firmly and accurately fix components to a board and improve work efficiency. It is to provide.

The method for fixing components according to the present invention uses a radiation-curing type packing agent as an adhesive for fixing components onto a substrate, and after applying the adhesive onto the substrate, it is irradiated with radiation to obtain sufficient adhesiveness. It is characterized in that the adhesive is applied to the adhesive, and the component is positioned at the component fixing position while being brought into close contact with the adhesive.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of fixing parts according to an embodiment of the present invention will now be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for members that are the same as or correspond to those shown in the conventional fixing method explained based on FIGS. 5 to 7.

As shown in FIG. 1, an adhesive 8 is applied to the parts fixing position on the printed circuit board 1. The adhesive 8 is, for example, a radiation-curable adhesive made of a modified acrylate resin as a main component and a polymerization initiator such as benzophenone added thereto, and it only develops adhesiveness when irradiated with radiation, in this case ultraviolet rays. , has the property that it is still in a liquid state before being irradiated with radiation, that is, at the time of application. After applying adhesive 8,
As shown in FIG. 2, the adhesive 8 on the printed circuit board 1
For example, 150 to 200+1 is applied by the ultraviolet irradiation device 9.
Irradiate with ultraviolet light of J/ci for a few seconds. By this irradiation with ultraviolet rays, the adhesive 8 becomes sticky.

Next, as shown in FIG. 3, the terminal 3a of the resistor 3 as a component to be fixed is inserted into the terminal insertion hole 1a formed in the printed circuit board 1, and while the resistor is brought into close contact with the adhesive 8. Position. Since the adhesive 8 has already developed adhesive properties by irradiation with ultraviolet rays, even if external vibration is applied to the printed circuit board 1 while the resistor 3 is in close contact with the adhesive 8, the resistor will remain in position. It never shifts. Note that the above-described adhesive application work, ultraviolet irradiation work, and component mounting work are performed on the same workbench without moving the printed circuit board 1.

The printed circuit board 1 on which each electronic component including the resistor 3 has been positioned in this way is conveyed to a solder tank by a conveyor or the like, and is immersed in the solder tank to form a circuit pattern on the printed board 1 as shown in FIG. 1b and terminal 3 of resistor 3
a and connect with solder 4.

In addition, in this example, ultraviolet rays were used as radiation,
Although we use adhesives that develop tackiness through this, it is also possible to use other radiation-curing adhesives, such as visible light, infrared rays, electron beams, or ion beams, and use compatible radiation-curable adhesives. It goes without saying that there is.

Further, after a component such as the resistor 3 is brought into close contact with the adhesive 8 that has developed tackiness, an even stronger radiation is irradiated to completely harden the adhesive protruding from the outer edge of the component until the tackiness disappears. It is also possible to prevent dust from adhering to this protruding adhesive.

In addition, Akebono peroxide is added as a catalyst to the radiation-curing adhesive, and the printed circuit board after fixing the parts is heated and polymerized in a heating furnace to promote complete curing of the adhesive. It is also possible to prevent dust from adhering to the adhesive side protruding from the outer edge of the adhesive. Note that examples of such modified oxides include benzoin peroxide, methyl ethyl ketone peroxide, and cumene hydroperoxide.

In addition, as a radiation-curable adhesive, C
Tll0 (registered trademark), CT10l-6 manufactured by Cemedine
(registered trademark), NVR-005 (registered trademark) manufactured by ThreeBond, and XP-55 (registered trademark) manufactured by Takeda Pharmaceutical Company.

Next, an example will be shown in which components were actually fixed to a substrate using IRCT110 manufactured by Cemedine and NVR-005 manufactured by ThreeBond, among the radiation-curable adhesives.

First, as a first example, a case where CT110 manufactured by Cemedine is used will be described.

0-110 is used as an adhesive as it is, and after irradiating it with ultraviolet rays with an energy of 150 mJ/i using an ultraviolet irradiation device as shown in Figure 2 to develop adhesive properties, it is used as a discrete electrolytic capacitor as an attachment part. was fixed on the printed circuit board. Thereafter, the printed circuit board was conveyed to a soldering tank by a belt conveyor and soldered. During this conveyance, the electrolytic capacitor did not come off or shift from the printed circuit board.

Furthermore, CT110 has sufficient heat resistance against the high heat applied in the soldering bath, and the electrolytic capacitor did not fall off due to melting.

Next, as a second example, NVR-005 manufactured by Three Bond
The case where is used as an adhesive will be explained.

In this case, 1 part by weight of benzoinveroxide was added as a heat curing catalyst to 100 parts by weight of NVR-005. After applying the adjusted adhesive onto a printed circuit board, it was irradiated with ultraviolet rays having an energy of 20011 J/- using an ultraviolet irradiation device to develop adhesive properties. Thereafter, the ceramic chip component was brought into close contact with the adhesive, and then the printed circuit board was carried into a heating furnace using a belt conveyor and heated at 140° C. for 3 minutes. The printed circuit board that had undergone this process was transferred to a soldering bath and soldered, but the chip components did not fall off in the soldering bath, and the chip components did not shift or come off on the printed circuit board even during transportation by the above-mentioned belt conveyor. Nothing happened.

As detailed above, in the component fixing method according to the present invention, a radiation-curable adhesive is used as the adhesive for fixing the component onto the substrate, and after the adhesive is applied onto the substrate, the This is irradiated with radiation in the field to develop sufficient adhesiveness in a short period of time, and the parts are brought into close contact with the adhesive and positioned at the part fixing position.

Therefore, the components are always firmly and accurately fixed to the board, and no component displacement occurs, improving work efficiency.

In addition, the radiation irradiation time required to make the radiation-curable adhesive develop the viscosity necessary for fixing parts is several seconds.
Compared to conventional fixing methods using heat-curing adhesives, which require several minutes to cure by heating, the work time is significantly reduced. Furthermore, the time required for conveying the adhesive to the heating furnace after applying the adhesive to the substrate, as in the conventional fixing method, is reduced, which also improves work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a state in which a radiation-curable adhesive is applied on a printed circuit board in the fixing method according to the present invention;
Figure 2 is a vertical cross-sectional view showing the adhesive being irradiated with radiation, Figure 3 is a vertical cross-sectional view showing the resistor being adhered to the adhesive, and Figure 4 is the resistor being soldered. The longitudinal sectional views showing the state and FIGS. 5 to 7 are diagrams for explaining the conventional fixing method. Explanation of symbols of main parts 1...Printed circuit board 1b...Circuit pattern 3...Resistor 4...Solder 8...Radiation curing Mold adhesive 9...Ultraviolet irradiation device 1 side 2 Kuni Atsushi 3 holes 4 holes

Claims (1)

[Claims] A step of applying a radiation-curable adhesive to a component fixing position on a substrate, a step of irradiating the radiation-curing adhesive to the radiation-curing adhesive, and a step of bringing the component into close contact with the radiation-curing adhesive and positioning the component at the component fixing position. A method for fixing parts, comprising the step of: